This specification applies to all models of LG LCD TVs: 32 ", 37", 42 ", with LA80A chassis.This LG 42LG700H or 42LG700-UA TV model is regarded as one of the best televisions manufactured by LG for its durability, simplicity at repair, a television with features for all purpose thanks to its ports of connection.
This television was one of those who possessed better technology, image quality, versatility and virtues at that time, so that even now, customers are investing in their recovery and start-up.
Unfortunately these televisions are remembered for the simple fact of consumerism and the application of new technologies on television, although there are still many people who need to give a solution to their devices and for them is this post.
Why does not my TV remove the hdmi cable?
First, check the wiring and to be more secure, it is best to change it or replace it. The other option is to try another device (Blu-ray, console) with an HDMI output because the one that does not give may be the cause and to reject it, it is necessary to try another device.
If the problem persists, unplug the TV for 20 minutes and reconnect ... these TVs when connected to the mains usually cause interruptions in operation and a simple way to reset the devices as capacitors is to disconnect from the mains.
Following the simple ways to solve this problem without being technical is to enter the menu and configure to make and restore the factory software.
Until now, the solution comes when you are not technical and the solution is external.
From here below, I show the form of the solution internally and being technical.
How to troubleshoot a TV that does not have an HDMI input
We started by examining the HDMI inputs that this TV has: the JK600 and the JK601. If it is in a faulty or broken state, this connector must be replaced. This connection port has 19 contacts that are usually generated by a bad connection or because the cable is incorrect and forced to force the TV connector to break. Check the voltage of the connector and pin 18, as this is where the 5v, marked by the red arrow in the image below, also takes into account the resistances indicated by the blue arrow and come from R603 to R612 and the other connector resistors from R613 to R622, since these resistors are of the fuse type and if one of them is open by protection we will also lose any interface between the two artifacts that we connect.
If the input is fine and everything is perfect here but we do not have any picture or sound, we keep checking the components and the second option would be the eeprom memories IC601 and IC602. This is the IC AT24C02. These devices are powered by 5vdc and they do it through leg 8, it is important to measure this voltage, because if we do not, it will not work in the mention mentioned.
If this voltage is not present in one of the two integrated circuits, we must raise the leg 8 of this device and check if it returns this voltage. If this is the case, it means that it is perhaps the integrated system that bypasses and causes the voltage to drop across it. If this voltage does not do this quick test, it means that it is the voltage somewhere cut, and not necessarily that the integration interferes in the drop of that voltage.
If the voltage would be, but there is no image on this HDMI port, it is possible that the settings of this memory have been erased, considering this point. Now, how do I remove the settings? ... simply extracted from the other eeprom that has the other port.
In the image below, I explained with a red arrow where this eeprom is powered and, with a blue arrow, I show the two zener diodes that have to be tested to verify that they are not crossed.
If everything goes very well here, continue with the measurements in the HDMI input area until you evaluate all the points and determine the reason for the problem.
This brings us to the HDMI-HDCP KEY MEMORY IC100, this is another eeprom. The CAT24C08WI, a memory of greater capacity than the two previously mentioned. It works with a 3.3v voltage, just as it is powered by leg 8 as shown by the red arrow in the picture below. The logical part indicated with the blue arrows, the SCL and in the SDA must be between 2v and 3.3v. As the image below shows, with these measures and observations, we can solve this fault. see.., that the negative connection is not the same as the other two memories, it is only in leg 4.
The explanations mentioned with the other memorials also apply to this with respect to its rejection and its test. If it is not resolved, you may need to change this POI.
As a penultimate step, we arrive at the integrated processors that would become IC603 and IC604, with the PI3HDMI341ART numbering. At this point, the only thing to do is check the power supply of these two integrated circuits. If these are fake or at least one of the two is not worth changing. These integrated ones have a coil in their power, and it is the coil L602, L603 and that which fulfills a very important function L601. When I mention that it is not worth changing this CI, I do not mean you can not, but it is possible not to find the integrated circuit, but it is at the discretion of each one , whether modified or not.
It should be mentioned that only one of the coils is shown in the image below, so that only coil L601 and L602 is shown, since the other is in the other IC.
As a final step, the problem could be in the main processor circuit that would become the BCM3563 IC, logically it would not make sense to achieve this. The only option would be to change the main board and this would solve the fault by which our TV does not show any signal through the HDMI input.
It should be mentioned that if we have problems in audio only, criticism and rejection are the same on what was done with the video.
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